A single generic mobility handling mechanism that allows roaming between all types of access networks would allow users to conveniently move between fixed and mobile networks, between public and private networks as well as between PLMNs with different access technologies. The ongoing work in the IETF Mobile IP working group is targeted towards such a mechanism. To offer Mobile IP(+) also to UMTS and GPRS users, a standard is needed for how to use Mobile IP in overlay to UMTS/GPRS.
Additionally, Mobile IP(+) could be used to handle mobility in the UMTS CN. Potentially, this would also allow cost savings for operators and a broadening of the market for manufacturers.
The present document is the result of two 3GPP-TSG SA-WG2 work items on Mobile IP:
"Combined GSM and Mobile IP mobility handling in UMTS IP CN", which main goal is to describe and evaluate an architecture that uses Mobile IP+ for mobility management and tunnelling within the CN. With respect to the work in IETF, a time scale for including this architecture in UMTS standards should be proposed;
"GPRS Mobile IP interworking", that aims at defining enhancements to the current GPRS standards to allow Mobile IP(+) to be used as an overlay to UMTS/GPRS for release 99.
Conclusions of the technical report is presented in clause 15.
The present document contains a feasibility study on using Mobile IP+ as a tunnelling and mobility management protocol in combination with GSM/UMTS mobility management in the packet domain of UMTS CN. A target architecture will be described and evaluated and the migration path from the current GPRS architecture towards the target architecture will be defined. It shall also describe the driving forces for moving from GTP towards Mobile IP+ as well as the benefits and disadvantages of the target architecture. A time schedule, i.e. UMTS releases, for the standardisation of such an architecture shall be proposed. Work on Mobile IP+ in the IETF should be taken into account.
This report will also contain a study on how to offer Mobile IP+ as an overlay to GPRS. This would allow an end user device, which is connected to the Internet (or intranet etc.) via LAN, to be reconnected during an active session via GPRS/UMTS or visa versa, without the need for any re-configuration or re-start of applications. The outcome of this part shall be part of UMTS release 99. Proposed solutions need to be balanced between the requirement to minimise the impact on the current GPRS standards and the requirements generated by further development of using Mobile IP+ within the CN in an efficient way. The output of this study is a description of the system and a set of CR's for those standards handled by 3GPP-TSG SA-WG2.